class Chemiq:
    """Chemiq reactions"""
    
    heat_joins = {'HH':4, 'HV':2, 'H-':3,
                  'VH':2, 'VV':2, 'V-':2,
                  '-H':3, '-V':2, '--':1 }
    
    @classmethod
    def heatJoin(cls, seq):
        if seq in cls.heat_joins:
            return cls.heat_joins[seq]
        else:
            return 0
    
